PRELIMS SNIPPETS – November 17th 2022
Why in News?
- Photonic crystal was recently developed by researchers that reflects vivid colours in the visible spectrum has potential applications in making more durable and better reflective displays and laser devices.
- Photonic crystals are optical nanostructures in which the refractive index changes periodically.
- Refractive index, also called index of refraction is the measure of the bending of a ray of light when passing from one medium into another.
- This affects the propagation of light in the same way that the structure of natural crystals gives rise to X-ray diffraction and that the atomic lattices (crystal structure) of semiconductors affect their conductivity of electrons.
- Photonic crystals occur in nature in the form of structural coloration and animal reflectors.
- Examples found in nature include opal, butterfly wings, peacock feathers, etc., exhibiting distinct iridescent colours.
- Photonic crystals promise to be useful in a range of applications ranging from reflection coatings to optical computers when artificially produced or engineered in laboratories.
- They enable the PCs to exhibit structural colours in the visible spectral regime.
- Researchers have also been on the constant lookout for tuning the properties in-situ post-fabrication.
- The development of advanced photonic materials and devices using Liquid Crystals (LC) that exhibit self-organization, phase transitions, and molecular orientation behaviors in response to external stimuli is attracting significant interest.